Java determina el tipo de valor del mapa

1. Cree una clase de prueba (TestMap1.java)

package com.jeff;

import java.util.HashMap;
import java.util.Map;

public class TestMap1 {

	public static void main(String[] args) {
		Map<String, Object> map = new HashMap<String, Object>();
		map.put("str", "Jeff");
		map.put("int", Integer.MAX_VALUE);
		map.put("long", Long.MAX_VALUE);
		map.put("float", Float.MAX_VALUE);
		map.put("double", Double.MAX_VALUE);
		map.put("u", new User("Jeff", "123456"));
		map.forEach((key, value) -> {
			if (value instanceof String) {
				System.out.println("String类型-->" + key + ":" + value);
			} else if (value instanceof Integer) {
				System.out.println("Integer类型-->" + key + ":" + value);
			} else if (value instanceof Long) {
				System.out.println("Long类型-->" + key + ":" + value);
			} else if (value instanceof Float) {
				System.out.println("Float类型-->" + key + ":" + value);
			} else if (value instanceof Double) {
				System.out.println("Double类型-->" + key + ":" + value);
			} else if (value instanceof User) {
				System.out.println("User类型-->" + key + ":" + value);
			}
		});
	}

}

class User {

	private String userName;
	private String password;

	public User(String userName, String password) {
		super();
		this.userName = userName;
		this.password = password;
	}

	public String getUserName() {
		return userName;
	}

	public void setUserName(String userName) {
		this.userName = userName;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	@Override
	public String toString() {
		return "User [userName=" + userName + ", password=" + password + "]";
	}

}

2. Resultados de salida de la consola